Desk frame

Abstract

A height adjustable desk including a work bench which is height adjustable and supported upon a pair of upwardly extending legs. The leg includes an upper portion supported on a lower portion. A height adjustment mechanism is manipulated by the user to adjust the height of the upper portion. This motion is transferred to the upper portion of the leg by means of cooperating rack gears meshingly engaged with their associated pinion gears. A shaft couples the gears so that the upper portions move in unison. The height adjustment mechanism includes a cooperating worm gear and nut. The worm gear is supported by the upper portion, while the nut is mounted in the lower portion.

What I claim is: 
     
       1. A height adjustment mechanism for a height adjustable desk having a pair of spaced legs to support a work bench, each leg including an upper portion to be fixed to the bench, and a lower portion to engage a surface supporting the desk, said mechanism comprising: a drive shaft having an extremity to be manipulated by a user to cause rotation of the shaft about its longitudinal axis;   means to rotatably support said shaft generally horizontally in said upper portion for rotation about its longitudinal axis;   a worm gear connected to said shaft so that said worm gear will rotate therewith about the longitudinal axis of the worm gear;   means to mount said worm gear in said upper portion so that said worm gear is generally vertically extending and is rotatable about its longitudinal axis;   a nut to be mounted on said lower portion and threadably engaged with said worm gear so that rotation of said worm gear causes movement of said nut along said worm gear so that in use said rotation causes vertical movement of said upper portion with respect to said lower portion;   a pedestal having said nut fixed to an upper end thereof, with said pedestal having a lower end to engage a respective one of the lower portions; and   a mounting bracket rotatable supporting an upper end of said worm gear, said bracket being fixed to a respective one of the upper portions.   
     
     
       2. The mechanism of claim 1, wherein said worm gear is connected to said shaft by a flexible drive. 
     
     
       3. The mechanism of claim 2, wherein said nut is mounted on a pedestal, so that upon installation in said lower part, said nut is spaced from said surface. 
     
     
       4. The mechanism of claim 3, further including a mounting bracket to be fixed to said upper part, and a bearing rotatably supporting said worm gear in said bracket. 
     
     
       5. The mechanism of claim 1, wherein said nut is mounted on a pedestal, so that upon installation in said lower part, said nut is spaced from said surface. 
     
     
       6. The mechanism of claim 5, further including a mounting bracket to be fixed to said upper part, and a bearing rotatably supporting said worm gear in said bracket. 
     
     
       7. A height adjustable desk having a frame, a work bench mounted on the frame, and a height adjustment mechanism to vertically adjust the height of the work bench; said frame comprising a pair of parallel upwardly extending legs which are horizontally spaced and generally co-extensive, each leg including an upper portion to be fixed to the bench, and a lower portion to engage a surface supporting the desk; and wherein   said height adjustment mechanism includes a drive shaft having an extremity to be manipulated by a user to cause rotation of the shaft about its longitudinal axis, means rotatably supporting said shaft generally horizontally in the upper portion of one of said legs for rotation about its longitudinal axis, a worm gear connected to said shaft so that said worm gear will rotate therewith about the longitudinal axis of said worm gear, means mounting said worm gear in the upper portion of said one leg so that said worm gear is generally vertically extending and is rotatable about its longitudinal axis, a nut mounted in the lower part of said one leg and threadably engaged with said worm gear so that rotation of said worm gear causes movement of said nut along said worm gear thereby vertically moving said upper portion of said one leg with respect to the lower portion of said one leg, a pedestal having said nut fixed to an upper end thereof, with said pedestal having a lower end fixed to said lower portion of said one leg, a mounting bracket notably supporting an upper end of said worm gear, said bracket being fixed to the upper portion of said one leg, and movement transfer means to cause a corresponding movement of the upper part of the other leg in unison with the upper part of said one leg.   
     
     
       8. The desk of claim 7, wherein said movement transfer means includes a first rack fixed to the upper part of said one leg, a first gear meshingly engaged with said first rack, said first gear being mounted on the lower part of said first leg, a second rack, said second rack being fixed to the upper part of said second leg, a second gear, said second gear being mounted on the lower part of said second leg and meshingly engaged with said second rack, a shaft fixed to said first gear and said second gear so that they rotate in unison to thereby cause movement of the upper part of said second leg in unison with the upper part of said first leg. 
     
     
       9. The desk of claim 7, wherein each upper part has a portion which is telescopically received within a portion of the associated lower part. 
     
     
       10. The desk of claim 7, further including a transverse brace extending between the two legs, and wherein the shaft extending between said first and second gears is located adjacent said transverse brace. 
     
     
       11. The mechanism of claim 7, wherein said worm gear is connected to said shaft by a flexible drive. 
     
     
       12. The mechanism of claim 11, wherein said nut is mounted on a pedestal, so that upon installation in said lower part, said nut is spaced from said surface. 
     
     
       13. The mechanism of claim 12, further including a mounting bracket to be fixed to said upper part, and a bearing rotatably supporting said worm gear in said bracket. 
     
     
       14. The mechanism of claim 7, wherein said nut is mounted on a pedestal, so that upon installation in said lower part, said nut is spaced from said surface. 
     
     
       15. The mechanism of claim 14, further including a mounting bracket to be fixed to said upper part, and a bearing rotatably supporting said worm gear in said bracket.